Molecular testing is a test carried out at the molecular level for detection of biological materials, such as DNA, RNA and/or proteins, in a test sample. Molecular testing is beginning to emerge as a gold standard due to its speed, sensitivity and specificity. For example, molecular assays were found to be 75% more sensitive than conventional cultures when identifying enteroviruses in cerebrospinal fluid and are now considered the gold standard for this diagnostic (Leland et al., Clin. Microbiol Rev. 2007, 20:49-78)
Microarrays are most prevalent in research laboratories as tools for profiling gene expression levels because thousands of probes can interrogate a single sample. Microarrays have not been widely adopted by clinical laboratories in molecular testing because of their operational complexity and cost (often hundreds of dollars per test). The high cost of microarray tests are due to three fundamental limitations: (1) the multi-step manufacturing process that often relies on photolithography (2) the device assembly, which frequently consist of glass or silicon substrates, and sometimes contains complex microfluidic designs to execute long sequence of steps, and/or (3) the labor associated with running these high complexity tests. Therefore, there exists a need for developing more cost effective methods and devices for performing molecular tests using microarray technology.